import java.util.Arrays;

public class Duoweisuzu {
    public static void main(String[] args) {
        int [][]ns = {
                {1,2,3,4},
                {5,6,7,8},
                {9,10,11,12}
        };
        System.out.println(ns.length);
        int[] arr0 = ns[0];
        System.out.println(arr0.length); // 4
        System.out.println(Arrays.deepToString(ns));

        int[][] scores = {
                { 82, 90, 91 },
                { 68, 72, 64 },
                { 95, 91, 89 },
                { 67, 52, 60 },
                { 79, 81, 85 },
        };
        // TODO:
        double average = 0;
        double sum = 0;
        int length  = scores[0].length*scores.length;
        for (int[] arrs:scores){
            for (int arr : arrs){
                sum += arr;
            }
        }
        average = sum/length;
        System.out.println(average);
        if (Math.abs(average - 77.733333) < 0.000001) {
            System.out.println("测试成功");
        } else {
            System.out.println("测试失败");
        }

    }
}
